Gear-wheel forging dies and method of making same



Oct. 16,1923; 1,470,818

J- E CKERT GEAR WHEEL FORGING DIES AND METHOD OF MAKING SAME Filed May 24. 1920 'Toallwhom it may mm:

Patented @ct l6, 1923 .ionnncnnn'r, or ILWAUKEE, W scons n, T

GEan-vrHEELron-Gmor pins AND newton; or Maxine sninn 1 Application filed Ma 24,

,Be it known that 1, JOHN ECKERT, a citizen of the United States, ,residing at Mil wa-ukce, county. of-Milwaukee, and State of l'Vi'scon'sin have invented new and. useful.

i Improvements in Gear-'WheeI Forging Dies and" Methods of Making Same, of which the following is a specification.

V ;My invention relates to improvements in gear wheel forging dies and methods of making the same." f f The object of my invention is toexpedite,

improve and cheapen the method of'manu fact'uring' gear wheels-and particularly to:

turingforging'.dies'having pattern teeth out;

provide an inexpensive method of manufactherein whereby 'piecesof heated metal may:

:be .hammered into' conformity with the pat! tern dies and the dies frequently replaced at "smallfexpense Wheii'they become Worm'or. distorted under the severe impacts to which "they m'ust be subjectedin order'to force the metal into perfect conformity with the pat 'tern. My. improved dies may be u'sd both asforging'hammers and as anvils,'in*fact j I'use them in both relationsfin a'single forging operation whereinthe' forging hammer embodying my improvement'i's first reciprocated into and out of contact" with ablock V of heated metal to forge itinto a circular blank having teeth thereon conforming gen? V iprovision of means wherebythegear tooth 'forming portion of the die may be readily I if erally to thecontour ofthedesired gear wheel and its teeth, after which the blank is placed bodying my. invention and 1a forging'hanimerreciprocated into contact with itsupp'er surface until the'teeth'have been pressed into 7 absolute or substantially-absolute conformity with thepaaem provided by the anvil die;

"Thelobject of my invention includes the out along radial lin'esfto form grooves, the

' walls of which eon-form perfectlyto the'contour of the teeth to beforged in a'n ordinary a gear tooth cutting machine or lathe, fthis fipolti o n of the die being separatelyvformed and subsequently assembled withthe central portion and in an outerportion concentric in which the teethproje'ct lateriallygfromone with the central and tooth carrying portions.

"contouring 1920.- S eirial no. 383,850.v I

thousands in a singleiday as the output from forge.

side thereoff'. Bevel dfl twh l a b produced at a rate of many hundredsor even 4 I In a companion application"bearing even Y datefherewith, Serial Number 383,849, filed 'May 2%,1920, 1' have shown and described 'a n'improvement in-gear-V wheels and methods" of manufacturing the same, in the practice of which method I employthe improved dies herein disclosed and illustrated infthejviac-fi icompanying l; drawings Wlth reference to which,niyinethod is'herelndescribed. J i

In the'drawings:

Fig 1' is a, verticalsectional, view of thje -i I V liarnmerfand anvil die of'a gear wheel fin-' i ishing forgewith the gear wheel inp'osition j and 'the'hammer in contact therewith, theanevil dieibeing constructed in a c'cordance with my invention. I

Fig; 2 is a tragmentary'view of a cylindricalblank from which the grooved portion ofrny 'improveddieis tolbe formed. V 7

- "Fig. 3 is a side view of the grooved por tion of the anvil die separated from itsconcentric central and outer portlons." 7

Fig. is a fragmentary sectional view showing the tooth forming portion of my improved die in assembledrelation to the central block or core piece as it appearspreparatory to applyingthe outer cylinder. Jinan inverted position upon an anvil die emg V '1 proved dies consists in first forminga cylindrical blankl having" at oneend a thick The method of manufacturing myimene dfp'ortionfl as shown in Fig, 2, both the' cnedpo'r tion The portionEZ conforms generally in its internal and external diameters of the toothed portion of the beveled gear wheel to be formed} This blank illustrated in Fig. 2 is/then placed'in alathe or gear,

cutting machine andf'radialgrooves 3 cut therein asshown in Fig. -The Walls of thesegrooves conform to the surfaces'of the 1gear teeth-tobe formed. They extend entirely across the thickened portion Qfrom V the outer to theinner side and they may", invention ispeculiarly adapted'to fathereforebe'readily cutina latheor gear termined by. cutting or shaping the end 2 of the cylinder, preferably before cutting the channels therein.

After cutting the portion 2 of the blank and conforming its surfaces to serve as a.

pattern die for the toothed portion of a beveled gear Wheel to beproduced in the forge, the cylinder is then heated and applied toa central cylindrical block or holder .5, as shown in Fig. 4. The outer surface of this block conforms tothe inner surface-of the blank shown; in Fig. 2, whereby, When the cylinder coolfs,; it will, shrink upon the block 5. It is obvious that by making the central block 5 of suflicient diameter so that :the cylinder when heated can be closely fitted thereto, the shrinkage of the cylinder.

as. it cools. willqcauseit to grip theblock withgreatforce, producing substantially an integral structure. Thereupon an outer ring or cylinder; 7 may be formed and V shrunk'upon the outer surface of the cylinder 1 in a similar 'manner.- Thisouter cylinder 7 is shaped at one end to conform :to the outer surface ofjthe enlarged portion -2"of-the cylinderl and both the central cylinder 5 and the outer cylinder 7 are so formed as toclose up the ends of the grooves 3,..Whereby the heated block or blank'o'f metal from which a gear Wheel is to be formed may be. hammered into these grooves and conformed thereto to produce the dc- I sired gear teeth on the blank.

As set forth in said companion application, a. die embodying the invent on herein described may be first employed as a forgin'g hammer to upsetgear teethon a block of heated metal while supported upon an anvil having a' circular recess, to the, con- "tour cf which the block of heatedmetal Will be conformed. during the hammering and *tooth upsetting process. Thereafter the heated block or blank maybe inverted and placed upon an anvil die also constructed in accordance With and embodying the invention herein disclosed and the upper surface of the blank hammered until the teeth dare brought into substantially perfect conformity to the rvalls of the grooves 3 in the die. .lVhenever a die becomes distortedor injuredby the forging operation, it may be immediately discarded and anotherdie substituted at small'expense for the reason that my improved process enables me to form the grooves 3 in .a lathe and subsequently; close up tlie'ends of the groovescwith the j inner and outer members 5 and 7, thus avoidingthe great expense which would bein r'olved in drilling, cutting and contouring the grooves in a single solid block of metal [having the form of the die shown in'Fig. 1.

l c laimz' IQThe method of making gear Wheel -fot'g1hg dles consisting in cuttingnthe end;v of a cylindrical blank along radlal lines to form grooves and intervening projections adapted to serve as a pattern for the toothed portion of a gear Wheel having laterally projecting teeth, heating said cylinder and shrinking the same upon a central cylindrical block conformed to the inner surface of the blank and adapted to close up the inner ends of said grooves, and subsequently shrinking a larger cylinder 'uponthe outer surfaceofthe groovedcylinderin a position to close up the outer ends of the grooves.

forging dies, which consists informing a cylindrical blank, with inner and. outer walls conlcally enlarged at one end and conformed in the inclination of its outer QQThe' method jof forming gear tivheel.

surface to the inclination or bevel of the toothed portion of a beveled gear wheel cutting radial-"grooves. n said contoured portion and conforming the surfaces of'the grooves and the intervening portions to serve as a pattern for the toothed portion L .of the gear wheel, va n d subsequently closingv the ends of the grooves with a central core" and enclosing cylinder.

I a The method of armingi'gsr theu forging dies, Whichconsists inl fir st forming a tooth shaping portion .having channels conforming 1n contour. to the ,gearteeth to be forged therein, andjthen uniting i tvvi'th other members of the die to provide rigid .closures for the ends of the channels, whereby a heated gear Wheel blank may be applied to the die and forged ou -the blank into exact conformity with the contour" of the die channels.

i. The method ofgforming gear ivh e elforging dies, which consists infirst forming a tooth shaping portion ,"having tooth shaped channels, andthen uniting it -v vith other members of the die to rigidly close the ends of such channels.

5. A gear Wheel forging die, the combination of a set of rigidlyconne'cted concentric members including a cent r al core an intermediate -WOIk forming member shrunk upon the core, and'anjouterivork forming member shrunk uponlthe intermediate member. s I

6 In agear-wheel'forging die, the combination with a cylindrical member having a conical end'provided with teeth, of a core for said cylindrical member, anda second cylindrical, member disposed about thefirst mentioned member, said core and second cylinder member being adapted to close the 7 ends of said teeth. 4 

